For fifty years, patients with cancer nave been staged and cancer statistics compiled based on how big the tumor is without consideration of how sick the patient is from comorbidity or other medical and health conditions. Recently, several national cancer organizations decided to include comorbidity information as a required data element for cancer registries. The American College of Surgeons Commission on Cancer (ACoS) mandated the collection of comorbidity information, using the ICD-9 system, from the hospital discharge "face sheet" beginning with cases abstracted after January 2003. However, extensive research has demonstrated that a claims^based approach to comorbidity collection is less accurate and complete than a chart-based approach. Since there is no single agreed upon method for collecting comorbidity information and selection of one method has trade-offs with other methods, it is a critical health policy question to compare the performance of a chart-based approach to a claims-based approach. The Goal of this research is to assess which comorbidity collection method, chart-based or claims- based, is the best for hospital-based cancer registries. The three Specific Aims of this research project are: 1. To assess the ability of a large number of cancer registrars in different hospitals and cancer care settings to learn chart-based comorbidity coding using the Web-Based Comorbidity Education Program. 2. To evaluate the reliability and validity of comorbidity coding using the approach taught in the Web- Based Comorbidity Education Program. 3. To compare chart-based comorbidity assessment with a claims-based approach using the ICD-9 coding system. We plan to enroll 75 cancer registrars at 13 different hospitals and health care systems across the United States. These registrars will complete the Web-Based Comorbidity Education Program and code comorbidity using the chart-based approach taught in the Program. The registrars will continue to code comorbidity using the ICD-9 system from the hospital discharge "face sheet as mandated by the ACoS. We plan to assess which comorbidity collection method is best for hospital-based cancer registries. We will also interview cancer specialists to ask them to evaluate the information provided by each approach, state which approach they prefer, and explain their reasons. We hypothesize that chart-based comorbidity information can be captured for a greater number of cancer patients, nave greater relevance to cancer care and outcomes, and have greater prognostic utility than claims-based information using the ICD-9 system. However, the chart-based approach requires special training and additional work by the cancer registrars. Assessment of the ability of cancer registrars to code comorbidity from the review of the medical record and the time required to do so is important. The research described in this application has significant health care policy implications because it could lead to improvements in the large-scale collection of cogent comorbid health information for newly diagnosed cancer patients by hospital-based cancer registrars.